/Engine/Source/Runtime/Engine/Public/UnrealClient.h
Reads the viewport's displayed pixels into a preallocated color buffer.
True if the read succeeded.
bool ReadLinearColorPixelsPtr ( [FLinearColor](API\Runtime\Core\Math\FLinearColor) * OutImageBytes, [FReadSurfaceDataFlags](API\Runtime\RHI\FReadSurfaceDataFlags) InFlags, FIntRect InRect )